ROS1 and cholangiocarcinoma: ROS1 (ROS1 proto-oncogene receptor tyrosine kinase) is activated through chromosomal rearrangement in a variety of human cancers, including glioblastoma multiforme, non–small-cell lung cancer (NSCLC), cholangiocarcinoma, gastric cancer, and ovarian cancer43, 44, 45, 46, 47.